Abrasion resistant omnidirectionally reflective pet leash

ABSTRACT

A flexible abrasion resistant omnidirectionally reflective pet leash has handle, central pet leash, and pet collar sections that reflect an incoming light beam back in the same direction as it was emanated. The reflected light beam provides accurate illumination of the pet owner&#39;s hand, pet leash and the location of the pet during dusk or nighttime hours. This pet leash is created by surrounding a central braided rope of nylon or polyethylene fibers with a cylindrically braided reflective sleeve that is coated with an abrasion resistant transparent polymeric coating. The braided reflective sleeve is composed of narrow width reflective strips that comprise narrow nylon or polypropylene sheets thermally bonded to a flexible polymeric sheet with attached corner cube or microsphere retroreflectors. Due to its braided construction, the reflective pet leash reflects light omnidirectionally over a large angle of acceptance, illuminating the pet owner&#39;s hand, the leash itself, and the pet&#39;s collar, thereby providing an improved measure of safety for both the pet and the pet handler.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.10/935,687, filed Sep. 8, 2004, now U.S. Pat. No. 6,925,965, which, inturn, claims the benefit of Application Ser. No. 60/591,936, filed Jul.28, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to pet leashes; and more particularly, toa abrasion resistant omnidirectionally reflective pet leash especiallysuited for use during dusk or nighttime hours to enhance safety of petsand their owners while walking in the vicinity of land vehicles.

2. Description of the Prior Art

Walking a pet during dusk or nighttime hours can be hazardous inneighborhoods where automobiles are encountered. Illuminatingcharacteristics of the automobile headlamps, generally afford anillumination range of approximately 25 to 50 feet. This illuminationrange can be significantly reduced by mist or fog, or bends in the road.Despite improvements to vehicle headlights, pets and their owners areoftentimes not recognized by automobile drives until the distancebetween the automobile and the pet is small.

Several approaches devised by prior art workers attempt to providesolutions for this hazardous common activity. These approachesinclude 1) use of pet collars that are illuminated or reflective; 2) useof leashes which are illuminated or reflective; or 3) a combination ofboth features. None of these solutions suggest indicating thewhereabouts of a pet owner, a leash and a pet attached to the leash viaomnidirectional reflection.

Various types of illuminated dog collars using bulb or other poweredsources are known in the art. These power-illuminated leashes requirebatteries, light bulbs or other lighting elements, which are not neededfor reflective illumination. Accordingly, a detailed discussion thereofis not required.

U.S. Pat. No. 4,173,201 to Chao et al. discloses an illuminated collarfor pets and the like. U.S. Pat. No. 4,513,692 to Kuhnsman et al.discloses an illuminated pet leash comprising a non-opaque tube thatcontains one or more bundles of optical fibers. U.S. Pat. No. 4,895,110to Lo Cascio discloses a pet collar that includes a light source and apower source attached to a strap. U.S. Pat. No. 4,887,552 to Haydendiscloses an electrically lighted pet leash that is composed of atransparent, flexible tube containing a string of small electric lightbulbs mounted in parallel between two insulated wires. U.S. Pat. No.5,046,456 to Heyman et al. discloses an illuminated pet collar in whichmultiple lights are mounted within a flexible, light-permeable tube thatextends about the perimeter of the collar. A housing mounted on one endof the tube contains a circuit and a battery for operating the lights.U.S. Pat. No. 5,140,946 to Pennock et al. discloses an illuminated petcollar with miniature lights powered by a battery encased within aflexible, pliable, transparent plastic display tube, which areparallel-wired within the display tube. U.S. Pat. No. 5,370,082, to Wadediscloses an animal collar that includes illuminating devices, such aslight emitting diodes, liquid quartz strips or electric lamps powered bya plurality of solar cells. U.S. Pat. No. 5,429,075 to Passarella et al.discloses a pet leash and flashlight combination. U.S. Pat. No.5,523,927 to Gokey discloses an illuminated animal collar light emittingdiode placed on the outer exterior of a collar powered by a battery.U.S. Pat. No. 5,535,106, issued to Tangen, discloses a lighted animalcollar that includes a plurality of separate light emitting assemblies,or housings, at spaced intervals along the collar. U.S. Pat. No.5,558,044 to Nasser, Jr. et al. discloses an illuminating leash handlewith a flashlight. U.S. Pat. No. 5,630,382 to Barbera et al. disclosesan illuminated pet harness having straps with internal cavities thatcontain fiber optic cores illuminated by a light bulb. U.S. Pat. No.5,762,029 to DuBois et al. discloses a combined retractable leash andflashlight. U.S. Pat. No. 5,850,807 to Keeler discloses an illuminatedpet leash, wherein illumination is remotely activated by a pet owner tolocate the leash. U.S. Pat. No. 5,967,095 to Greves discloses anelectroluminescence-illuminated pet flat leash strap. U.S. Pat. No.6,170,968 to Caswell discloses a motion activated rotatable illuminator.U.S. Pat. No. 6,289,849 to Macedo et al. discloses a device forremovably attaching a flashlight to a retractable dog leash. U.S. Pat.No. 6,557,498 to Smierciak et al. discloses a night safety petillumination marker, with a pet collar having a series of light emittingdiodes mounted around the perimeter of the collar and powered by batterypower.

Various types of dog collars illuminated by reflection are known in theart. Representative dog collars of this variety are discussed below.

U.S. Pat. No. 3,871,336 to Bergman discloses a reflective dog collarwhich is not illuminated; but which utilizes a highly reflectivematerial having the form of different color dots encapsulated inplastic. This illuminates only portions of the flat planar pet collar.

U.S. Pat. No. 3,999,521 to Puiello discloses a reflective safety harnessfor quadruped animals. The harness includes a pair of identical sheetelements with a light reflective surface mounted on opposite sides ofthe animal. At the corners of the sheet are fastened straps, whichcircumscribe the animal's body at the front and rear of the harness.Extending from the front strap, at the top point thereof, midway betweenthe two elements, is a loop through which the dog's regular collar ispassed. The arrangement assures immovable attachment of the harness onthe dog's body. The disclosure by the '521 patent of a reflective sheetpositioned on both sides of the animal does not suggest a pet collar ora leash that reflects incident light.

U.S. Pat. No. 4,167,156 to Kupperman et al. discloses a reflectiveanimal leather leash. The elongated leather animal leash includes a sewna transparent polyvinyl chloride strip with a light reflective prismdesign on one surface. The light reflective prism is bonded bydielectric heat sealing or sonic welding to an opaque polyvinyl chloridestrip sewn to the leather strip, resulting in a leash having a lightreflective surface. Since the strip has a reflective surface on only oneside of the leash, it does not reflect light in every direction. Theflat leather leash is not easily twistable and is not readily bentwithout separating the transparent and opaque polyvinyl chloride layers.

U.S. Pat. No. 4,384,548 to Cohn discloses a safety device for animals. Apet collar uses “retro-reflective” threads with glass reflectiveelements in a flexible webbing to form a pet leash. The threads are saidto reflect incident light directly back toward the source. Dispositionof reflective threads in the webbing forming the collar is sparce. As aresult, the quantum of incident light reflected is small; and aninsignificant quantum of incident light is reflected back to the source.

U.S. Pat. No. 4,407,233 to Bozzaco discloses a safety collar for pets.The collar has highly reflective flexible elements with a length largeenough to extend beyond the outer surface of the pet's hair. It usesflexible elements with Scotchlite reflecting strips attached to acollar. A reflective pet leash is not disclosed, and the flexibleelements do not reflect light in every direction.

U.S. Pat. No. 5,243,457 to Spencer discloses a material with enhancedvisibility characteristics. This flexible visibility enhancing materialcombines the advantages of a light reflective component and aluminescent component. The material includes a first layer of prismaticlight reflective plastic material having an underlying surface formedwith a plurality of minute prism-like formations projecting there fromat regular spaced intervals, and an overlying substantially smooth lighttransmissive surface. Bonded, i.e. by heat-sealing, to the first layeris a second layer of plastic luminescent material. The second layer iscontiguously and integrally attached to the underlying surface of theprism-like formations and generally coextensive therewith. Thevisibility enhancing material simultaneously radiates luminescent lightfrom the second layer through the underlying surface of prism-likeformations and through the smooth light transmissive surface andreflects light from the prism-like formations through the smooth lighttransmissive surface. In one embodiment, a leash for controlling andrestraining a pet animal includes a flexible elongate member comprisedof the visibility enhanced material. In another embodiment, the secondlayer is replaced with a layer of luminescent material, which can beselectively energized to become luminous. Since the transparentreflective material is a molded plastic of prismatic construction it isrigid and is not flexible and does not form a leash that is capable ofbeing twisted and bent. Further any twisting and bending actionseparates the reflective element from the luminescent element.

U.S. Pat. No. 5,237,448 to Spencer et al. discloses a visibilityenhancing material. The flexible visibility enhancing material combinesthe advantages of a light reflective component and a luminescentcomponent. The material includes a first layer of prismatic lightreflective plastic material having an underlying surface formed with aplurality of minute prism-like formations projecting therefrom atregular spaced intervals, and an overlying substantially smooth lighttransmissive surface. A second layer of plastic luminescent material iscontiguously and integrally attached to the underlying surface of theprism-like formations and generally coextensive therewith. Thevisibility enhancing material simultaneously radiates luminescent lightfrom the second layer through the underlying surface of the prism-likeformations and through the smooth light transmissive surface, andreflects light from the prism-like formations through the smooth lighttransmissive surface. In one embodiment, a leash for controlling andrestraining a pet animal includes a flexible elongate member comprisedof the visibility enhanced material. Since the transparent reflectivematerial is a molded plastic of prismatic construction, it is rigid andis not flexible and does not form a leash that is capable of beingtwisted and bent. Furthermore, any twisting and bending action willresult in separation of the reflective element from the luminescentelement.

U.S. Pat. No. 6,070,556 to Edwards discloses an illuminating dog safetysystem. This illuminating dog safety system is designed for allowing ananimal to be more visible at night. The device includes a collar that isworn around a neck of an animal. The collar has a reflective stripextending a majority of its length. A harness is provided that isadapted to be worn around a torso of the animal. The harness iscomprised of an upper strap member, a lower strap member, and alongitudinal extension there between. The upper strap member, the lowerstrap member, and the longitudinal extension each have a reflectivestrip extending a majority of a length thereof. A leash is provided thatis adapted for securement to the collar. The leash has a reflectivestrip extending a majority of its length. All these strip elements aremade from flat elements, as shown in FIG. 3 of the patent disclosure.Twisting the elements does not provide the reflectivity needed foradequate visibility at night.

Numerous patents disclose reflective materials. Some of these patentsdisclose reflective elements having corner cube shapes embedded in arigid or flexible polymeric strips and monolayers of spherical beads,i.e. primarily glass beads bonded to a reflective sheet.

U.S. Pat. No. 3,176,584 to DeVries et al. discloses that a reinforcinglayer may be incorporated into an embedded lens retroreflectivesheeting. The reinforcing layer may be of a similar composition as thebinder in which the microspheres are embedded. The layer may be appliedto the back side of the secularly reflective layer via spraying, i.e.,by a solvent-coating technique. Examples of the reinforcing layermaterials disclosed include methyl methacrylate, flexible epoxy resins,chloro-sulfonated polyethylene, polystyrene, polypropylene,polycarbonate resin, ethyl cellulose, and cellulose acetate-butyrate.The reflective layer is typically very thin and fragile, i.e. in theorder of 0.06 microns thick, and must be disposed in specialrelationship to the microspheres in order for the sheeting to provideuseful retro-reflection.

U.S. Pat. No. 3,190,178 to McKenzie discloses a reflex reflectivesheeting. It uses a monolayer of microspheres embedded in a polymer toreflect the incoming light beam in the same direction as the incidentbeam. Since the sheet is formed by melting of the polymeric binder, itis rigid and therefore unsuitable for flexible pet leashes.

U.S. Pat. No. 4,025,159 to McGrath discloses cellular retroreflectivesheeting. The cellular retroreflective sheeting comprises a base layerof retroreflective elements and a transparent cover film supported inspaced relation away from the base layer by a network of narrowintersecting bonds. These bonds form hermetically sealed cells withinwhich retroreflective elements are isolated from retroreflectiveelements of different cells. The resultant sheeting achieves greaterdurability through use of bonds that are cured in situ after they havebeen thermoformed into sealing contact between the cover film and baselayer. The base material is coated with the binder, subjected to heatand pressure to displace the binder around the embedded microsphers orcorner cubes forming the bonded network. Retroreflective articles soconstructed may be rigid and inflexible.

U.S. Pat. Nos. 4,576,850 to Martens, and 4,582,885, 4,668,558 to Barberdisclose a shaped plastic articles having replicated microstructuresurfaces. This shaped plastic article is made by crosslinked polymerwith hard and soft segments having a microstructure-bearing surface thatis replicated, with a castable fluid, and radiation hardened. Articlesformed by this process exhibit, a retro-reflective cube-corner sheeting,Fresnel lens or video disc. All these formed articles are rigid andtherefore unsuitable for use in pet leashes. Moreover, these articlesalso exhibit low tear strength.

U.S. Pat. No. 4,763,985 to Bingham discloses a launderableretroreflective appliqué that comprises a layer of transparentmicrospheres, a specular reflective layer optically connected to eachmicrosphere, and a binder layer into which the microspheres arepartially embedded. Resins disclosed as being suitable for use as binderlayers include polyurethane, polyesters, polyvinyl acetate, polyvinylchloride, acrylics, or combinations thereof. The specular reflectivelayers are composed of two succeeding layers of dielectric material. Thelayers have varying refractive indices and are composed of a variety ofbinary metal compounds including oxides, sulfides, and fluorides.

U.S. Pat. No. 4,815,818 to Thomas discloses three-dimensional flexiblereflectors. The reflector is provided with elastomeric resilient memberwith a plurality of embedded retro-reflective glass beads. A portion ofthe outer surface of the elastomeric material is removed to expose theglass beads. The exterior surface of the glass beads at the outersurface is exposed and is subject to abrasion.

U.S. Pat. No. 4,950,525 to Bailey discloses elastomeric retroreflectivesheeting. The elastomeric retroreflective sheeting has a monolayer ofnon-stretchable microspheres. These microspheres are embedded in a sheetwith a spacing layer of transparent elestomeric material underlying theback surface of the microspheres. A cover layer of transparentelastomeric material covers the front surface of the microspheres. Aspecularly reflective layer is disposed on the back surface of thespacing layer. The cover layer comprises a clear thermoplasticelastomeric aliphatic polyurethane.

U.S. Pat. No. 4,957,335 to Kuney discloses microsphere-basedretro-reflective articles having high retroreflective brightness atnarrow divergence or observation angles, i.e. up to 0.5 degrees. Thearticle is made by selection of microspheres having defined combinationsof average diameter and average refractive index. This patent teaches(column 4, lines 18–23) that variation in the size of the microsphereswill increase the observation angle or divergence angle of the resultantretro-reflective article.

U.S. Pat. No. 5,066,098 to Kult et al. discloses cellularencapsulated-lens high whiteness retroreflective sheeting with aflexible cover sheet. This cellular, encapsulated-lens retroreflectivesheeting comprises a base sheet of a monolayer of retroreflectiveelements that is partially embedded in a binder layer which typically iswhite. A cover sheet is disposed in spaced relation from the layer ofretroreflective elements. A network of narrow intersecting bonds, orseal legs, that extend between the cover sheet and the base sheet withbinder material are thermoformed at the point of contact between thebase sheet and cover sheet. Such a rigid, reflective sheet is unsuitablefor pet leashes, which require structures that can twist and flex.

U.S. Pat. No. 5,117,304 to Huang et al. discloses a retroreflectivearticle. The retroreflective article has corner cubes and is flexible,and can be applied over irregular surfaces by using an optically clear,aliphatic polyurethane polymer. The aliphatic polymer has a plurality ofhard chain segments having the formula —C(O)N(H)—C₆ H₁₀—N(H)C(O)—.

U.S. Pat. No. 5,200,262 to Li discloses a launderable retroreflectiveappliqué. The appliqué employs a reflector that comprises elementalaluminum or elemental silver on the backside of the microspheres. Theappliqué comprises a monolayer of metal-coated microspheres partiallyembedded in and partially protruding from a binder layer. The binderlayer comprises a flexible polymer having hydrogen functionalities andone or more isocyanate-functional silane coupling agents. The disclosedflexible polymers that possess hydrogen functionalities are crosslinked,flexible urethane-based polymers, such as isocyanate-cured polymers orone or two component polyurethanes and polyols.

U.S. Pat. No. 5,283,101 to Li discloses a launderable retroreflectiveappliqué comprising a binder layer formed from an electron-beam curablepolymer and typically one or more crosslinkers and silane couplingagents. Electron-beam curable polymers include chlorosulfonatedpolyethylenes, ethylene copolymers comprising at least about 70 weightpercent of polyethylene, such as ethylene/vinyl acetate,ethylene/acrylate, and ethylene/acrylic acid, andpoly(ethylene-co-propylene-co-diene) polymers. Glass microspheres areembedded in the cured binder layer, and a specular reflective metallayer is disposed on the embedded portions thereof. When the appliqué isinverted, light comes through the binder layer.

U.S. Pat. No. 5,777,790 to Nakajima discloses a microsphere-basedretroreflective article. The retroreflective article comprises amonolayer of microspheres partially embedded in and protruding from abinder layer and specular reflector underlying the microspheres. Themonolayer of microspheres comprises a mixture of a first class ofmicrospheres having a first refractive index and a second class ofmicrospheres having a second refractive index. The second refractiveindex is higher than the first refractive index. As a result, thesheeting exhibits superior observation angle angularity.

U.S. Pat. No. 5,882,796 to Wilson et al. discloses bonded structuredretroreflective sheeting. The structured retroreflective sheetingincludes an array of corner cube structured retroreflective elements, athermoplastic sealing film located proximate the structured elements,and bonding agent between the sealing film and the structuredretroreflective elements. The bonding agent bonds the sealing film tothe structured retroreflective film. This bonded structure is rigid andis unlikely to survive the flexing and twisting movements of a petleash.

U.S. Pat. No. 5,926,314 to Smith et al. discloses a retroreflective cubecorner article having scalene base triangles. The cube cornerretroreflective article exhibits a wide range of retroreflectiveentrance angularity in at least one plane, and preferably in two or moreplanes. The structured surface has an array of cube corner elementsformed by three intersecting sets of substantially parallel grooves.Each cube corner element includes a base triangle bonded by one groovefrom each of the three intersecting groove sets, the base triangle beingscalene. The corner cube reflector is rigid and cannot be used forproducing reflective leashes.

U.S. Pat. No. 5,962,108 to Nestegard et al. discloses a retroreflectivepolymer coated flexible fabric material and method of manufacture. Theretroreflective polymeric coated flexible fabric material has aretroreflective layer and a polymeric compatibilizing layer welded to apolymeric coated outer surface of a flexible fabric material. Thecompatibilizing layer provides an intermediate layer between theretroreflective layer and the flexible fabric material, creatingsuitable bond strength between dissimilar polymers. Flexible fabricmaterials are polyester, nylon or cotton. The fabric is coated withhighly plasticized polyvinyl chloride (PVC) or ethylene acrylic acidcopolymer (EAA). These polymers are flexible, durable, and resistant toabrasion. The retroreflective prismatic elements layer includes: acrylicpolymers, such as poly(methylmethacrylate); polycarbonates; cellulosics;polyesters such as poly(butyleneterephthalate);poly(ethyleneterephthalate); fluoropolymers; polyamides;polyetherketones; poly(etherimide); polyolefins; poly(styrene);poly(styrene) co-polymers; polysulfone; urethanes, including aliphaticand aromatic polyurethanes; and mixtures of the above polymers such as apoly(ester) and poly(carbonate) blend, and a fluoropolymer and acrylicpolymer blend. The compatibilizing layer that is suitable for bondingbetween a retroreflective layer and a flexible fabric material include:polyurethane, ethylene methyl acrylate copolymer, ethylene N-butylacrylate copolymer, ethylene ethyl acrylate copolymer, ethylene vinylacetate copolymer, polymerically plasticized PVC, and polyurethaneprimed ethylene acrylic acid copolymer. Such a reflective fabric doesnot suggest the shape, construction or function of a pet leash.

U.S. Pat. No. 5,910,858 to Frey discloses retroreflective sheeting witha coated back surface. The retroreflective sheet has a plurality ofindentations on the back surface to reflect the light, and a transparentfront surface to encapsulate and protect the light reflectingindentations. This reflective sheet is rigid and is unsuitable for usein pet leashes.

U.S. Pat. No. 6,159,537 to Crandall discloses a method of making aretroreflective article that has a binder layer containing an epoxyresin and silicone crosslinked polymer. A pre-binder compositioncomprises about 5 to about 40 parts of an epoxy resin. About 60 to about95 parts of an alkoxysilane terminated polymer is applied to aretroreflective layer and then cured to form a binder layer that isadhered to the retroreflective layer and an article of clothing. Thebinder composition does not cover the exterior surface of the reflectivelayer and does not provide abrasion resistance.

U.S. Pat. No. 6,677,028 to Lasch, et al. discloses retroreflectivearticles having multilayer films and methods of manufacturing same.These retroreflective articles have multilayer films and are useful forcommercial graphics and retroreflective products, such as roll-up signsfor highway transportation safety. The articles comprise multilayerfilms having at least one layer of polyurethane and a core layer of acopolymer of alkylene and a bond layer of non-acidic, polar co-monomerincluding, ethylene copolymer, vinyl acetate, acrylate, EVA,acid-modified EVA, anhydride-modified EVA, acid-acrylate-modified EVA,anhydride-acrylate-modified EVA, EEA, EMA, AEA, EVACO, EBACO, and EnBA.The glass retroreflective beads comprise an air-exposed portion or havean overlay polyurethane or EAA cover film. When retroreflective glassbeads are exposed to air, they are subject to wear.

Notwithstanding the efforts of prior art workers to construct petleashes and pet collars that are illuminated by incident light, thereremains a need in the art for a flexible abrasion resistant pet leashthat omnidirectionally reflects a significant quantum of incoming lightback to its source. Numerous methods for producing retroreflectors havebeen disclosed. A flexible pet leash having a robust construction thatwithstands tensile and torsional forces attending leash usage, has longbeen needed in the art. Also needed is a flexible, omnidirectionalabrasion resistant pet leash capable of maintaining high reflectivitywhen subjected to surface abrasion from frictional forces created bycontact of the leash with objects having rough exteriors, such as theground, flooring, posts, trees and the like

SUMMARY OF THE INVENTION

The present invention provides a pet leash that is abrasion resistantand omnidirectionally reflective. Omnidirectional reflectivity isprovided by the incorporation of retroreflective corner cube reflectorsor microsphere reflective elements. With this structure, the leashreflects a significant quantum of the incident light from a car headlight or other light emitting element back to the source. The abrasionresistance property of the pet leash is provided by a transparentcoating. One such coating comprises a polymer that is transparent,flexible and has a refractive index significantly smaller than that ofthe retroreflective elements used. Abrasion resistance andomnidirectional reflectivity is achieved by: a) creating a flexibleretroreflective sheet comprising a plurality of corner cube reflectorsbonded via a transparent bond to a flexible polymeric sheet, or severalmicrospheres bonded via a transparent bond to a reflectorized flexiblepolymeric sheet; b) producing a narrow width strip composed of nylon orpolypropylene fibers by knitting, weaving or braiding, to achieve astrip width in the range of 0.0065 inch to 0.25 inch, depending upon thesize of the central cylindrical rope core; c) thermally bonding theflexible retroreflective sheet to the narrow width strip to form anarrow width reflective strip; d) cylindrically braiding, at a shallowbraid angle, three or more narrow width reflective strips to surroundand cover the external surface of a central cylindrical leash core madefrom braided nylon or polypropylene fibers; e) forming a cylindricalretroreflective braided sleeve integrally surrounding a centralcylindrical leash core to thereby create a leash having an externalretroreflector surface; and f) coating the external surface of thecylindrical retroreflective braided sleeve with a transparent, flexibleabrasion resistant coating having a refractive index significantly lessthan that of the retroreflective elements. The thickness of thetransparent abrasion resistant coating is in the range of 0.002 to 0.010inches.

The proximal end of the leash is formed into a loop that defines a leashhandle. The retroreflective cylindrical braiding sleeve present on thehandle is seamlessly braided, closing the loop. Thus the handle alsoreflects the incident light from a car's headlights back to the sourceilluminating the position of the hand that is holding the pet. Thedistal end of the leash is attached to mechanical hardware, such as ametallic ring, forming a choke collar that encircles the neck of the petcreating a retroreflective collar. In a second embodiment, the distalend of the leash has an adjustable metallic strip with one or more holeslocations that lock with a pet leash clamp forming a reflective petcollar that is non-choking. The transparent abrasion resistant coatingmay be applied to the entire length of the pet leash between theproximal and distal ends.

The cylindrical character of the flexible cylindrical braided sleevereflects a significant quantum of incident light back to the sourceeffectively since some portion of the braided sleeve is always at anglesclose to normality and most of the braided cylindrical sleeve fallswithin the reflecting angular range of the retroreflectors. The shallowbraiding angle of the cylindrical braid sleeve lays the thermally bondednarrow width strips at a shallow angle with respect to the length of thecylindrical central core. As a result the leash can be readily flexed ortwisted due to the relative movement provided within the cylindricalbraid sleeve structure. The flexibility of the transparent abrasionresistant coating provides for flexing and twisting movement of theabrasion resistant pet leash without coating separation or delamination.

The external surface of the cylindrical retroreflective braided sleeveis coated with a transparent, flexible abrasion resistant polymericcoating. The coating has a refractive index significantly lesser thanthat of retroreflective elements. Typically the retroreflective elementshave a refractive index of 1.9 to 2.2 and the flexible transparentabrasion resistant polymeric coating has a refractive index of 1.3 to1.55. A 0.002 to 0.010 inch layer of transparent flexible abrasionresistant polymeric coating does not affect the path of normallyincident incoming light beam. With such a coating alteration of the pathof inclined incident light beam is minimal. Similarly, the reflectedlight beam path is not severely affected. The internal reflectionproperty of the retroreflective elements is not deteriorated since theabrasion resistant coating has significantly lower refractive index, ascompared to that of the retroreflective elements.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be more fully understood and further advantages willbecome apparent when reference is had to the following detaileddescription of the preferred embodiments of the invention and theaccompanying drawings, in which:

FIG. 1 a is a photograph of the leash showing a leash with thereflective cylindrical braided sleeve of narrow width strips covering acentral core forming a leash handle, pet leash central section, andchoke collar section, taken with camera flash light showing reflectiveportions as bright regions;

FIG. 1 b is a photograph of the leash showing a leash with thecylindrical reflective braided sleeve of narrow width strips covering acentral core forming a leash handle, pet leash central section and chokecollar section, taken without camera flash light showing reflectiveportions as dark regions;

FIG. 2 is a photograph of the leash illustrating the details of atransparent abrasion resistant polymeric conformal coating substantiallycovering the reflective cylindrical braided sleeve of narrow widthstrips surrounding a central pet leash core;

FIG. 3 is a photograph of the proximal end of the leash forming a loopthat functions as a light reflecting handle with reflective cylindricalbraided sleeve of narrow width strips.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides abrasion resistant pet leash that isflexible, twistable and omnidirectionally reflective. It has anintegrally formed handle in the proximal end of the leash, which is alsoomnidirectionally reflective. The distal end of the pet leash has a ringthat is integrally braided into the leash forming a choke pet collar.The handle, pet leash, and the choke collar of the pet leash are allomnidirectionally reflective reflecting incident light back to itssource, thereby clearly defining the pet owner's hand that has theleash, the pet leash and the neck portion of the pet that carries thechoke collar. This increases the margin of safety in dusk or night timeenvironments when a car headlight can illuminate the owner walking a petand the pet, reducing the possibility of accidents. Since theomnidirectionally reflecting pet leash reflects light over a broadrange, due to its reflective cylindrical sleeve arrangement, theheadlight can be at a significant angle and could still be reflectedback.

The abrasion resistant omnidirectional pet leash is constructed bybuilding a cylindrically reflective sleeve from narrow width strips ofnylon or polypropylene. These narrow width strips are thermally bondedto a polymeric flexible sheet with a plurality of retroreflectingelements. The retroreflecting elements may be corner cubes, in whichcase the polymeric flexible sheet can be non-reflective. Alternatively,the retroreflecting elements may be microspheres. If microspheres areused as retroreflective elements, the polymeric flexible sheet needs tobe reflective and is typically metallized with aluminum or silver. Ineither case, the retroreflective elements are bonded to the flexiblesheet using a transparent binder.

The flexible sheet with retroreflective elements is available from 3Mcorporation. The trade name for this product is SCOTCHLITE and theflexible polymer is typically PVC and the product is available in avariety of sizes. This flexible reflectorized sheet is thermally bondedto a braided, woven or knitted narrow width nylon or polypropylenestrip. The strip may have a width of 0.0065 inches to 0.25 inches and isthermally bonded to a SCOTCHLITE strip having a similar width. Thethermal bonding binder may be selected from a number of polymericbinders including, but not limited to, polyvinyl chloride, polyethylene,polyurethane, polyvinyl acetate or acrylates. The bonded narrow widthstrip is highly flexible and can be cylindrically braided, surrounding acentral rope core of the leash, which substantially sustains the petpulling tensile forces.

The cylindrical braiding employs three or more thermally bonded narrowwidth strips with flexible reflective strips. The cylindrical braidingis accomplished with a small angle between narrow width strips and thelongitudinal direction of the central core rope. The proximal end of thecentral core of the leash is fashioned to form a loop representing ahandle, and the distal end is formed to go through a metallic loop tocreate a choke leash. The cylindrical braiding is accomplished to coverthe entire length of the pet leash, including the handle and the chokecollar hardware. The ends of the braid are terminated by permanentbonding.

In an alternate embodiment, the portion of the pet leash near the distalend carries an adjustable metallic tab component having one or moreapertures. The distal end of the leash carries a typical pet leashclamp, which engages with one or more apertures in the metallic tab.This construction provides pet collar having a non-choke function andomnidirectional reflectivity.

A transparent abrasion resistant coating is applied to the outer surfaceof the cylindrically braided reflective strips of the pet leash and isapplied as a substantially conformal coating. The reflective strips haveretroreflective elements embedded in the strips having a corner cubeprismatic or microsphere geometry. These transparent retroreflectiveelements are made from high refractive index transparent materials suchas barium oxide-titanium oxide containing glasses. They exhibit arefractive index in the range of 1.9 to 2.2. The transparent abrasionresistant polymeric coating is selected to have a refractive index,which is significantly less than that of the retrorefractive elements.As a result, the incident and reflected light path is not significantlyaltered even when the incident beam is inclined to the reflectivestrips. The internal reflection process within the retroreflectiveelements is not deteriorated by the transparent abrasion resistantcoating. The polymers suitable for use with the transparent abrasionresistant coating have a refractive index in the range of 1.3 to 1.55.

In addition to this refractive index requirement, the transparentabrasion resistant coating must exhibit excellent mechanical properties,including tensile strength and elongation, in order to provide therequired abrasion resistance. The polymer coating must also exhibitsuperior bond properties to the retroreflective elements and theunderlying polymeric sheet of the reflective strip. If the bondproperties are poor, the transparent abrasion resistant coating maydelaminate when the pet leash is subjected to abrasion or flexing andtwisting movement. The transparent abrasion resistant coating must havelow elastic modulus so that it remains flexible when the pet leash istwisted. A high modulus transparent abrasion resistant coating is notdesired since it applies significant stresses at the coating-reflectivetape interface resulting in deterioration or fracture of theretroreflective elements.

A number of polymer systems meet these requirements. These polymers maybe applied by dipping the cylindrically braided pet leash in a polymericmelt or by spraying a polymer composition dissolved in a suitablesolvent. Thermosetting resin compositions such as two-componentpolyurethane may be painted or sprayed over the cylindrically braidedreflective outer surface of the pet leash. In Table A below there arelisted a number of transparent polymer compositions suitable for the petleash abrasion resistant coating. Also listed are the refractive indexesfor the compositions.

TABLE A Polymer Name Refractive Index aliphatic thermoplastic 1.35 to1.45 polyurethanes Dow Corning OE-4100 1.4751 Silicone elastomerPolymethyl tetradecyl siloxane 1.4550 Poly vinyl acetate 1.4665 PMMAPoly methyl 1.4893 methacrylate Cellulose acetate 1.4750 Ethylene/vinylacetate 1.4820 copolymer EVA

Thermoplastic aliphatic thermoplastic polyurethanes are preferred ascompared to aromatic urethanes because of their transparency, resistanceto dirt build-up, flexiblility ultraviolet radiation degradationresistance. Typically, aliphatic polyurethane has the structure

[—O—(CH(CH₃)CH2O₂₀—C(O)—NH—R—NH—C(O)—]; or

[—O—(CH₂—CH₂CH₂ CH₂—O—)₁₀—C(O)—NH—R—NH—C(O)—], where R is a non-aromaticgroup.

Rohm and Haas, (Morton International Inc) supplies melt extrudablepolyurethane compositions under the trade name designation MORTHANEL430.77 and MORTHANE Brand PN 3429-215. A melt extrusion process may beused to coat the external surface of the cylindrically braidedreflective sleeve

Aptec Laboratories, 28570, Livingston Avenue, Valencia Calif.91355-4171. 661-257-1677 markets polyurethane with low elastic modulusfor conformal coatings. Two component APTEK transparent unfilledpolyurethane compositions of interest include the composition 2503-A/B(www.apteklabs.com/products/2503-AB.pdf) and the composition 2506-A/B(www.apteklabs.com/products/2506.pdf). These two compositions aredesigned for the encapsulation and protection of devices in applicationsthat require toughness, excellent flexibility and optimum tensilestrength, as well as elongation characteristics. APTEK 2503-A/B iscurable at 80 C while APTEK 2506-A/B is room temperature curable. Bothcompositions are dissolved in a solvent and are therefore suitable forbrush or spray application.

Bayer provides a number of clear polyurethane coating compositions basedon one component or two component systems. Desmodular I aliphaticdiisocyanate is often abbreviated to IPDI, CAS 4098-71-9. Polyurethaneprepared from IPDI is clear, tough and resists photodegradation andhydrolysis. Isocyanurate based on IPDI is marketed by Bayer under thetrade name Z-4470; and is available in a number of solvent blends. Twocomponent polyurethane is commonly formulated with Desmodur Z-4470.Desmodur E polyisocyanates is a single component moisture curable systemcapable of being diluted in a solvent.

www.setcochemicals.net/resins4.htm. supplies flexible room temperaturecuring polyurethane coatings ROTOTHANE® 9020. This coating adheres toplastics and leather.

Dow Corning supplies a number of silicone compositions suitable forcoating the cylindrically braided reflective strips to provide abrasionresistance. Conformal coatings are materials applied in thin layers(typically a few mils or a fraction of a mm) onto printed circuits orother electronic substrates. They provide environmental and mechanicalprotection to significantly extend the life of the components andcircuitry. Conformal coatings are traditionally applied by dipping,spraying or simple flow coating, and increasingly by select coating orrobotic dispensing. Key requirements for the clear coating are lowviscosity; enabling application of thin conformal coatings, roomtemperature cure in reasonable cure time and reasonable hardness. InTable B below there are shown some of the conformal silicone coatingsmarketed by Dow Corning.

TABLE B Product One part/ Viscosity Name Two part CPS Cure Durometer3-1965 1 110 RT 24 Hrs 29 A Moisture cure 3-1953 1 360 RT 24 Hrs 26 AMoisture Cure 3-1765 1 150 RT 24 Hrs 25 A Moisture cure 3-1753 1 385 RT24 Hrs 25 A Moisture cure Sylgard 2 450 20 min/85° C. 64 OO 1-4128I-4105 1 470 10 min/105° C. 65 OO QI-4010 1 830 15 min/110° C. 30 AI-2620 1 250 RT 72 Hrs 25 D Abrasion Resistant I-2577 1 1250 RT 72 Hrs25 D LOW Abrasion VOC Resistant I-2577 1 725 RT 72 Hrs 23 D AbrasionResistant

Candidates for silicone conformal coating compositions that meet the lowviscosity in the range of 100–250 CPS, room temperature cure inreasonable time period and reasonable hardness are coating compositions3-1965., 3-1765 and I-2620. These compositions may be dipped, brushpainted or sprayed.

Of particular interest is a Dow Corning OE-4100 optical siliconeelastomer, which cures in 2 hour at 150 C with a platinum basedcatalyst, as discussed inwww.dowcorning.com/content/photonic/75-1009B-01.pdf. This composition isspecifically developed for use in the optical coating of opticalcomponents and is clear, transparent with a refractive index of 1.47.

Polyvinyl acetate is soluble in acetone as well as toluene. Acetonedissolved polyvinyl acetate film has a slightly higher elastic modulusas compared to that dissolved in toluene due to rapid evaporation ofacetone. Acetone dissolved polyvinyl acetate is applied to thecylindrically braided surface of the pet leash to form a flexible filmwhich is resistant to twisting action of a pet leash. Polyvinyl acetateis available from Union Carbide under the trade names AYAC, AYAA, AYAFand AYAT depending upon the molecular weight of the polymer.

FIG. 1 a is a photograph of the pet leash at 10 showing the handlesection 11, the central pet leash section 12, and the choke collarsection 13. A cylindrically braided sleeve, created from braided narrowwidth reflective strips, covers each of these sections (11, 12, and 13),providing substantially the entire surface of the leash withomnidirectional reflectivity. The leash completely reflects incidentlight in the same direction the light was emanated. Due to thecylindrical character of the reflective braided sleeve, some portion ofthe sleeve is always at normal orientation to the incoming light beam,that is, the direction at which the reflection from the retroreflectiveelements is maximized. Retroreflective elements reflect light over alarge range of acceptance angles, but the reflection is at a lowerintensity. This cylindrical construction effectively reflects theincoming camera flash light as shown in the photograph of FIG. 1 a bythe extremely bright appearance of the retroreflectors 16 (see also FIG.2) of the leash.

FIG. 1 b shows a photograph of another view of the omnidirectionalreflective pet leash without using a camera flash. The illuminationcomes from the room's light, as evidenced by the shadow, “S”, of themetallic ring in FIG. 1 b. The light here, again, is reflected back tothe illuminating source, and practically no light is directed in thedirection of the camera. As a result, the retroreflector bright areas ofFIG. 1 a now appear dark.

FIG. 2 is a photograph of a magnified portion of the central pet leashsection 12. The photograph shows the a transparent abrasion resistantpolymeric conformal coating 14 substantially covering the reflectivecylindrical braided sleeve of narrow width strips surrounding a centralpet leash core. The cylindrical reflective braided sleeve is braidedwith a small braid angle of 5 to 10 degrees between the narrow widthstrips surrounding the central cylindrical rope core of the leash. Thecentral cylindrical rope core is completely covered by the cylindricalreflective braided sleeve and therefore is invisible in the photograph.The flexible retroreflective sheet is shown at 16 and the narrow widthstrip is shown at 15. The flexible retroreflective sheet 16 is thermallybonded to the narrow width strip 15 prior to cylindrical braidingoperation. The outer surface of the retroreflective sheet 16 and thenarrow width strip is covered with a transparent conformal flexibleabrasion resistant coating 14.

FIG. 3 shows the details of the handle portion 11 of theomnidirectionally reflective pet leash. The loop of the centralcylindrical braided rope core is completely covered by the cylindricalreflective braided sleeve and the ends of the braid are terminated bybonding to each strip at 17.

The key features of the abrasion resistant omnidirectionally reflectivepet leash includes, in combination, the features set forth below:

1. a pet leash comprised of a central cylindrical braided rope corecomposed of braided nylon or polypropylene fibers capable of sustainingtensile forces developed by pet leash loads;

2. the central cylindrical braided rope core being covered substantiallywith a transparent abrasion resistant conformal coating applied to acylindrically reflective braided sleeve;

3. the cylindrically reflective braided sleeve formed by cylindricallybraiding narrow width reflected strips, formed from knitted, woven orbraided nylon, or polypropylene narrow width strips, having thermallybonded flexible retroreflector sheets bonded to the surface thereof;

4. each of the flexible retroreflector sheets being prepared by bondingcorner cube geometry retroreflectors to a flexible polymeric sheet usinga transparent binder;

5. such flexible retroreflector sheets alternately being prepared bybonding microsphere geometry retroreflectors to a metallized reflectiveflexible polymeric sheet using a transparent binder;

6. twist and flexure forces acting on the abrasion resistantomnidirectionally reflective pet leash being accommodated by the braidedconstruction of the cylindrical reflective sleeve and the flexibility ofabrasion resistant coating;

7. the cylindrical braided sleeve-covered pet leash substantiallyreflecting incident light back in the same direction as the incidentlight, clearly indicating the whereabouts of the pet leash handle, petleash central portion, and the pet leash collar surrounding the neck;

8. the abrasion resistant omnidirectionally reflective pet leashproviding an increased margin of safety for pets and their owners whilewalking in dimly lit environments, such as parking garages, or inclementweather conditions, where rapidly moving vehicles are encountered.

The abrasion resistant omnidirectionally reflective pet leash disclosedherein can be modified in numerous ways without departing from the scopeof the invention. For example, at least one strip of the central bradedrope core can be composed of leather. The pet collar can be integralwith the central rope core or detachable therefrom via fastening meansin the conventional way. These and other modifications are intended tofall within the scope of the invention, as defined by the subjoinedclaims.

Having thus described the invention in rather full detail, it will beunderstood that such detail need not be strictly adhered to, but thatadditional changes and modifications may suggest themselves to oneskilled in the art, all falling within the scope of the invention asdefined by the subjoined claims.

1. A reflective pet leash, comprising: a. a central cylindrical braidedrope core operable to sustain substantial tensile forces; b. acylindrical reflective braided sleeve comprising three or more narrowwidth reflective strips that are braided at a shallow cylindrical braidangle, said cylindrical reflective braided sleeve being operable tosurround said central cylindrical braided rope core thereby providingomnidirectional reflectivity; c. said cylindrical reflective braidedsleeve substantially coated with a conformal transparent polymericabrasion resistant coating; d. said narrow width reflective stripscomprising a woven or knitted narrow width strip and a flexibleretroreflective sheet, said woven or knitted narrow width strip having ashow surface, and said flexible retroreflective sheet being thermallybonded onto said show surface thereof; e. said flexible retroreflectivesheet having retroreflectors bonded thereto with a transparent bondlayer; f. said transparent polymeric abrasion resistant coating having arefractive index lower than that of said retroreflectors; and g. saidleash having a proximal end and a distal end, the proximal end beinglooped and braided to form an omnidirectionally reflective handle, andthe distal end being looped and braided and attached to a metallichardware component operable with said rope core and surrounding braidedsleeve to form a pet collar having omnidirectional reflectivity.
 2. Areflective pet leash as recited by claim 1, wherein said centralcylindrical braided rope core comprises braided nylon fibers.
 3. Areflective pet leash as recited by claim 1, wherein said centralcylindrical braided rope core comprises braided polypropylene fibers. 4.A reflective pet leash as recited by claim 1, wherein said cylindricalreflective braided sleeve is braided at a braid angle of 5 to 10degrees.
 5. A reflective pet leash as recited by claim 1, wherein eachof said narrow width reflective strips has a width of 0.0065 to 0.25inches.
 6. A reflective pet leash as recited by claim 1, wherein saidflexible retroreflective sheet is thermally bonded to said woven orknitted narrow width strip with polyvinyl chloride.
 7. A reflective petleash as recited by claim 1, wherein said flexible retroreflective sheetis thermally bonded to said woven or knitted narrow width strip withpolyvinyl acetate.
 8. A reflective pet leash as recited by claim 1,wherein said flexible retroreflective sheet is thermally bonded to saidwoven or knitted narrow width strip with polyurethane.
 9. A reflectivepet leash as recited by claim 1, wherein said flexible retroreflectivesheet comprises a plurality of corner cube retroreflectors.
 10. Areflective pet leash as recited by claim 1, wherein said flexibleretroreflective sheet comprises a plurality of microsphereretroreflectors bonded to a light-reflecting sheet.
 11. A reflective petleash as recited by claim 1, wherein said retroreflectors have arefractive index in the range of 1.9 to 2.2.
 12. A reflective pet leashas recited by claim 1, wherein said transparent polymeric abrasionresistant coating has a refractive index in the range of 1.3 to 1.55.13. A reflective pet leash as recited by claim 1, wherein saidtransparent polymeric abrasion resistant coating has a thickness in therange of 0.002 to 0.010 inches.
 14. A reflective pet leash as recited byclaim 1, wherein said transparent polymeric abrasion resistant coatingpolymer is a member selected from the group consisting of polyurethane,silicone, polymethyl methacralate, and polyvinyl acetate.
 15. Areflective pet leash as recited by claim 14, wherein said polyurethaneis aliphatic polyurethane.
 16. A reflective pet leash as recited byclaim 14, wherein said polyurethane is melt extruded.
 17. A reflectivepet leash as recited by claim 14, wherein said polyurethane is dissolvedin a solvent and sprayed on the said cylindrical reflective braidedsleeve.
 18. A reflective pet leash as recited by claim 14, wherein saidsilicone comprises a silicone composition having a viscosity in therange of 100–275 CPS.
 19. A reflective pet leash as recited by claim 1,wherein said pet collar functions as a choke collar.
 20. A reflectivepet leash as recited by claim 1, wherein said metallic hardwarecomponent comprises an adjustable metallic tab having a plurality ofapertures connected to a pet leash clamp thereby forming a pet collarhaving non-choke functionality and omnidirectional reflectivity.
 21. Aprocess for manufacture of a reflective pet leash, comprising the stepsof: a. selecting a braided nylon or polypropylene cylindrical centralrope, said cylindrical central rope having a proximal end, a distal end,and an external surface; b. forming a loop at said proximal end of saidcentral rope, to thereby form a handle; c. attaching said distal end toa mechanical hardware component, said mechanical hardware componentoperating with said central rope to form a pet collar; d. selecting aflexible polymer sheet; e. coating said flexible polymer sheet with aplurality of retroreflectors using a transparent binder to form aretroreflector coated flexible polymer sheet; f. thermally bonding saidretroreflector coated flexible polymer sheet to a woven or knittednarrow width strip to form a narrow width reflective strip; g. braidingat least three of said narrow width reflective strips at a shallowcylindrical braid angle to form an omnidirectionally reflective sleevehaving a braided construction; h. applying a transparent flexiblepolymeric abrasion resistant conformal coating to substantially coversaid omnidirectionally reflective sleeve; and i. covering said handle,said pet collar, and said external surface of said cylindrical centralrope with said omnidirectionally reflective sleeve to said pet leashwith omnidirectional reflectivity; said omnidirectionally reflective petleash being operable to sustain abrasion, substantial tensile forces,and to accommodate twist and flexure forces due to strength and movementafforded by said braided construction of said omnidirectionallyreflective sleeve.